A probate search reveals she died on 14 July 2019
She was the unm dau of John Francis BLAKISON CIE (1882-1965), scion of the Blakiston Baronets (GB 1763) being descended from the 2nd son of the 2nd Bt, and (m as his 2nd w 1937) Margaret Dora WARD-JACKSON (d 1991)
Funeral notice from the Daily Post, Wales (translated from the Welsh, not by me)
Susan Anne Margaret BLAKISTON
BLAKISTON - SUSAN ANNE MARGARET, . July 14th,2019. [?] at Ysbyty Gwynedd and from Anelog Farm, near Aberdaron, at the age of 79. Public service at Bangor Crematorium, Thursday, July 25th at 2-15 pm. No flowers, but donations are gratefully received in memory of Susan towards the 'British Polio Society' through the undertaker R O Jones,Talafon,Tudweiliog,Pwllheli,LL53 8NE.01758 770456